642 



PHYSIOLOGY OF THE CEREBRUM 



muscles of the body. Further investigations along this line have given us 

 the following results: 



The spasm begins always in the group of muscles whose cortical area is 

 stimulated, and from there spreads in a perfectly regular manner to the other 



muscles. If, for example in the dog, 

 the left cortical area for movements of 

 the eyelids is stimulated, the attack 

 begins in the eyelids of the opposite 

 side, and from there passes to the 

 face muscles. As a result the head 

 is turned to the right, whereupon the 

 spasm extends to the right anterior, 

 and then to the right posterior ex- 

 tremity. Then for the first the mus- 

 cles of the left side are affected and 

 the spasm spreads in reverse order 

 from below upward, sweeping over 

 the muscles of the posterior, then 

 of the anterior extremity, and so on 

 until, last of all, the muscles of the 

 eyelids on the left are reached. 



Fig. 291 may be cited as showing 

 the characteristics of the cramplike 

 contractions. As will be seen, it is 

 at first tonic, later becoming clonic 

 in character. A sleepy condition or 

 a condition of great agitation may 

 ensue as an after-effect. 



The attacks appear on prolonged 

 stimulation, sometimes while the 

 stimulation is in progress and some- 

 times after it has ceased. They may 

 appear also " spontaneously " when 

 superficial lesions are made within 

 the motor zone and the animal is 

 kept alive ; after the wound is healed 

 the epileptic attacks come on without 

 stimulation. 



Likewise in man cortical epilepsy 

 occurs as the result of irritative le- 

 sions of the motor zone, and on the 

 whole is of about the same char- 

 acter as that following artificial 

 stimulation in animals. This is dis- 

 tinguished from the usual form of 



epilepsy, by the retention of consciousness at least at the beginning of the at- 

 tack, and sometimes throughout its whole course. The patient feels the attack 

 approaching, and can protect himself from injuries while it is on. 



